The invention relates to a method for operating a wheel suspension system of a motor vehicle as well as to a system for operating a wheel suspension system of a motor vehicle.
If a motor vehicle travels over an uneven path, energy is usually dissipated via the dampers of a chassis of the motor vehicle. However, it is possible to recuperate and thus recover energy via appropriate damper designs.
The power of the damper is first considered for calculating the energy to be recuperated. The power is a product of a force and a speed of the damper. Integrating the power over time results in the energy. If the energy to be recuperated is to be as high as possible in a uniform time interval, either the force or the speed of the damper must be high, wherein however only the force of the damper can be directly influenced.
A method for operating a motor vehicle is known from the printed document DE 10 2009 036 731 A1. Described therein is that electrical energy, which is recuperated via a damping of a wheel, is subject to great fluctuations and high peak values. Therefore, an actuator with a power electronics and a short-term memory is provided for each wheel of the motor vehicle, so as to be able to convert relative movements of the wheel into electrical energy based on road irregularities.
An electrically adjustable control for a damper is known from the printed document DE 101 20 918 B4. In this case, a position of the damper is adapted to the specific driving situation for maximum possible comfort, wherein the specific driving situation is determined, for example, from sensors which detect road unevenness.
The printed document DE 10 2010 052 964 A1 shows a method for operating a propulsion and/or braking system of a motor vehicle, wherein with this propulsion and/or braking system, energy is recuperated via an energy storage device inside the vehicle as a function of a detection device, which detects objects in an environment of the motor vehicle.
Furthermore, recuperating damper systems are known from the printed documents U.S. 2009/0260935 A1 and WO 2011/159874 A2.
A system for generating a damping force as part of a wheel suspension system of a motor vehicle is known from the printed document U.S. 2009/0079145 A1. The system includes hereby a first device which has an electromagnetic motor and is designed to generate a first damping force. In addition, the system includes a second device for generating a second damping force which depends on an action of a liquid when a speed of a lifting movement matches a speed by which an electrically driving force which is generated by the electromagnetic motor exceeds a voltage of a voltage source.
A damping device for a motor vehicle is known from the printed document U.S. 2013/0158799 A1. This motor vehicle is hereby equipped with a forecast sensor which is designed to detect a convex area on a roadway before it is driven over by a wheel of the motor vehicle. When the convex portion is driven over, a stiffness of the damping device, for example, a spring, is adapted to the convex portion, whereby ride comfort is to be enhanced.
U.S. Pat. No. 8,840,118 B1 describes an active suspension system that has a hydraulic actuator, a hydraulic motor pump, an electric motor that is coupled to the hydraulic motor pump, a sensor for ascertaining a state of a wheel, and a control device for controlling the preceding components. The electric motor converts hereby electric energy only when the hydraulic actuator is actively moved.